Saturday Genetics Quiz #13: Types of Mutations
This week’s question:
What are some of the major types of mutations/DNA alterations?
Answer:
A single base pair change is called a point mutation and directly affects the function of a single gene and can be categorized into:
- Missense mutation - results in a protein in which one amino acid is substituted for another
- Nonsense mutation - a stop codon replaces an amino acid codon, leading to premature termination of translation
- Frameshift mutation - causes a change in the reading frame leading to introduction of unrelated amino acids into the protein, generally followed by a stop codon
Small deletions of a few base pairs also affect single genes and can cause frameshift mutations or mutations which lead to the loss of amino acids.
Chromosomal mutations affect overall chromosome structure and involve multiple genes, often resulting in major physiological changes. Genes may be deleted or inserted, inverted, or exchanged between chromosomes.
For more information about mutations, see Molecular Cell Biology by Harvey Lodis et al.
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2 opinions for Saturday Genetics Quiz #13: Types of Mutations
Genetics and Health » The Genes of X-Men
May 5, 2006 at 1:38 pm
[…] The article is about a form of oxidation (8-oxoG) causing DNA damage, specifically single nucleotide polymorphisms (SNPs) and recombinations between chromosomes. These types of mutations (and many others) are how humans evolved from slime mold to modern homo sapien and continue to evolve into who knows what form we’ll take (X-men?!) if we don’t self-destruct. […]
Genetics and Health » Weekly Genetics Quiz #49: Cancer is Genetic
Jul 23, 2006 at 10:46 am
[…] Although all cancer is caused by mutations in specific types of genes (oncogenes, tumor suppressor genes, and DNA repair genes), not all of these mutations are inherited. Only about 1-2% of cancers are hereditary and cluster in families with a strong shared susceptibility. Most people have sporadic cancer without a positive family history of the disease. […]
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